| 摘要 |
A process for preparing an Lagerstroemia speciosa L. extract of low bitterness comprising, contained in Lagerstroemia speciosa L. as a blood sugar level increase inhibiting component, corosolic acid or corosolic acid plus ellagitannin in high proportion. This process comprises the steps of (1) extracting Lagerstroemia speciosa L. with a hydrous organic solvent, concentrating the obtained extract and dispersing the concentrate in a hydrous organic solvent, (2) subjecting the dispersion to solid/liquid separation and performing fractionation into an insoluble matter and a soluble matter, (3) extracting the insoluble matter with an alkali hydrous organic solvent and collecting the extract, and (4) treating the extract with an acid and collecting precipitates. |
